Elastic binding polymers for electrochemical cells

Abstract

The present disclosure relates to an electrochemical cell having an elastic binding polymer that improves long-term performance of the electrochemical cell, particularly when the electrochemical cell includes an electroactive material that undergoes volumetric expansion and contraction during cycling of the electrochemical cell (such as, silicon-containing electroactive materials). The electrochemical cell can include the elastic binding polymer as an electrode additive and/or a coating layer disposed adjacent to an exposed surface of an electrode that includes an electroactive material that undergoes volumetric expansion and contraction and/or a gel layer disposed adjacent to an electrode that includes an electroactive material that undergoes volumetric expansion and contraction. The elastic binding polymer may include one or more alginates or alginate derivatives and at least one crosslinker.

What is claimed is: 
     
         1 . An electrochemical cell that cycles lithium ions comprising:
 an electrode comprising an electroactive material that undergoes volumetric expansion and contraction during cycling of the electrochemical cell; and   an elastic interlayer disposed adjacent to an exposed surface of the electrode, wherein the elastic interlayer comprises an elastic binding polymer, wherein the elastic binding polymer comprises one or more alginates and at least one crosslinker.   
     
     
         2 . The electrochemical cell of  claim 1 , wherein the one or more alginates comprise:
 (a) an alginate salt selected from the group consisting of: lithium alginate, sodium alginate, potassium alginate, ammonium alginate, and combinations thereof;   (b) a grafted alginate selected from the group consisting of: polyacrylamide-g alginate, polyacrylate-g-alginate, polyvinylpyrrolidone-g-alginate, dodecylamide-g alginate, and combinations thereof;   (c) an alginate derivatives comprising an alginate backbone having been subjected to at least one of oxidation, reductive-amination sulfation, coupling of cyclodextrin of hydroxyl groups and esterification, Ugi reactions, and amidation of carboxyl groups; or   (d) any combination thereof.   
     
     
         3 . The electrochemical cell of  claim 1 , wherein each crosslinker comprises a multi-valence cation selected from the group consisting of: Ca 2+ , Mg 2+ , Al 3+ , Zn 2+ , Fe 2+ , Fe 3+ , and combinations thereof, and
 an anion selected from the group consisting of: Cl − , SO 4   2− , NO 3   − , and combinations thereof.   
     
     
         4 . The electrochemical cell of  claim 1 , wherein the elastic binding polymer comprises:
 greater than or equal to about 95 wt. % to less than or equal to about 99.99 wt. % of the one or more alginates, and   greater than or equal to about 0.01 wt. % to less than or equal to about 5 wt. % of the at least one crosslinker.   
     
     
         5 . The electrochemical cell of  claim 1 , wherein the electrode further comprises greater than 0 wt. % to less than or equal to about 20 wt. % of the elastic binding polymer. 
     
     
         6 . The electrochemical cell of  claim 1 , wherein the elastic interlayer has a thickness less than or equal to about 50 μm and the electrode has a thickness greater than or equal to about 1 μm to less than or equal to about 1000 μm. 
     
     
         7 . The electrochemical cell of  claim 1 , wherein the elastic interlayer is a gel layer having a thickness less than or equal to about 10 μm. 
     
     
         8 . The electrochemical cell of  claim 1 , wherein the electroactive material is a silicon-containing electroactive material. 
     
     
         9 . The electrochemical cell of  claim 1 , wherein the exposed surface is a first exposed surface and the electrochemical cell further comprises a current collector disposed adjacent a second exposed surface of the electrode, wherein the second exposed surface is substantially parallel with the first exposed surface. 
     
     
         10 . An electrochemical cell that cycles lithium ions comprising:
 an electrode comprising:
 an electroactive material that undergoes volumetric expansion and contraction during cycling of the electrochemical cell; and 
 an elastic binding polymer comprising one or more alginates and at least one crosslinker. 
   
     
     
         11 . The electrochemical cell of  claim 10 , wherein the one or more alginates comprise:
 (a) an alginate salt selected from the group consisting of: lithium alginate, sodium alginate, potassium alginate, ammonium alginate, and combinations thereof;   (b) a grafted alginate selected from the group consisting of: polyacrylamide-g alginate, polyacrylate-g-alginate, polyvinylpyrrolidone-g-alginate, dodecylamide-g alginate, and combinations thereof;   (c) an alginate derivative comprising an alginate backbone having been subjected to at least one of oxidation, reductive-amination sulfation, coupling of cyclodextrin of hydroxyl groups and esterification, Ugi reactions, and amidation of carboxyl groups; or   (d) any combination thereof.   
     
     
         12 . The electrochemical cell of  claim 10 , wherein each crosslinker comprises a multi-valence cation selected from the group consisting of: Ca 2+ , Mg 2+ , Al 3+ , Zn 2+ , Fe 2+ , Fe 3+ , and combinations thereof, and
 an anion selected from the group consisting of: Cl − , SO 4   2− , NO 3   − , and combinations thereof.   
     
     
         13 . The electrochemical cell of  claim 10 , wherein the elastic binding polymer comprises:
 greater than or equal to about 95 wt. % to less than or equal to about 99.99 wt. % of the one or more alginates, and   greater than or equal to about 0.01 wt. % to less than or equal to about 5 wt. % of the at least one crosslinker.   
     
     
         14 . The electrochemical cell of  claim 10 , wherein the electrochemical cell further comprises:
 an elastic interlayer disposed adjacent to an exposed surface of the electrode, wherein the elastic interlayer is a gel layer comprising the elastic binding polymer.   
     
     
         15 . The electrochemical cell of  claim 14 , wherein the elastic interlayer has a thickness less than or equal to about 50 μm and the electrode has a thickness greater than or equal to about 1 μm to less than or equal to about 1000 μm. 
     
     
         16 . An electrochemical cell that cycles lithium ions comprising:
 a negative electrode comprising a negative silicon-containing electroactive material and having a thickness greater than or equal to about 1 μm to less than or equal to about 1000 μm;   a current collector disposed adjacent to a first exposed surface of the negative electrode; and   an elastic interlayer having a thickness less than or equal to about 50 μm disposed adjacent to a second exposed surface of the negative electrode, wherein the second exposed surface is substantially parallel with the first exposed surface, the elastic interlayer is a gel layer comprising an elastic binding polymer, and the elastic binding polymer comprises one or more alginates and at least one crosslinker.   
     
     
         17 . The electrochemical cell of  claim 16 , wherein the one or more alginates comprise:
 (a) one or more alginate salts selected from the group consisting of: lithium alginate, sodium alginate, potassium alginate, ammonium alginate, and combinations thereof;   (b) one or more grafted alginates selected from the group consisting of: polyacrylamide-g alginate, polyacrylate-g-alginate, polyvinylpyrrolidone-g-alginate, dodecylamide-g alginate, and combinations thereof,   (c) one or more alginate derivatives comprising an alginate backbone having been subjected to at least one of oxidation, reductive-amination sulfation, coupling of cyclodextrin of hydroxyl groups and esterification, Ugi reactions, and amidation of carboxyl groups; and   (d) any combination thereof.   
     
     
         18 . The electrochemical cell of  claim 16 , wherein each crosslinker comprises a multi-valence cation selected from the group consisting of: Ca 2+ , Mg 2+ , Al 3+ , Zn 2+ , Fe 2+ , Fe 3+ , and combinations thereof, and
 an anion selected from the group consisting of: Cl − , SO 4   2− , NO 3   − , and combinations thereof.   
     
     
         19 . The electrochemical cell of  claim 16 , wherein the elastic binding polymer comprises:
 greater than or equal to about 95 wt. % to less than or equal to about 99.99 wt. % of the one or more alginates, and   greater than or equal to about 0.01 wt. % to less than or equal to about 5 wt. % of the at least one crosslinker.   
     
     
         20 . The electrochemical cell of  claim 16 , wherein the negative electrode further comprises greater than 0 wt. % to less than or equal to about 20 wt. % of the elastic binding polymer.